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Minegishi Y, Nishimoto J, Uto M, Ozone K, Oka Y, Kokubun T, Murata K, Takemoto H, Kanemura N. Effects of exercise on muscle reinnervation and plasticity of spinal circuits in rat sciatic nerve crush injury models with different numbers of crushes. Muscle Nerve 2022; 65:612-620. [PMID: 35119696 DOI: 10.1002/mus.27512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 01/22/2022] [Accepted: 01/29/2022] [Indexed: 11/10/2022]
Abstract
INTRODUCTION/AIMS Motor function recovery is frequently poor after peripheral nerve injury. The effect of different numbers of nerve crushes and exercise on motor function recovery is unknown. We aimed to examine how different numbers of crushes of the rat sciatic nerve affects muscle reinnervation and plasticity of spinal circuits and the effect of exercise intervention. METHODS Single and multiple sciatic nerve crush models with different numbers of crushes were created in rats. Treadmill exercise was performed at 10 m/min for 60 min, five times a week. Muscle reinnervation and synaptic changes in L4-5 motor neurons were examined by immunofluorescence staining. Behavioral tests were the sciatic functional index (SFI) and the pinprick tests. RESULTS The percentage of soleus muscle reinnervation was not significantly increased by the presence of exercise in single or multiple crushes. Exercise after a single crush increased the contact of motor neurons with VGLUT1-containing structures (Exercised vs. Unexercised, 12.9% vs. 8.7%; P < 0.01), but after multiple crushes, it decreased with or without exercise (8.1% vs. 8.6%). Exercise after a single crush significantly improved SFI values from 14 to 24 days, and exercise after multiple crushes from 21 to 35 days (all P < 0.05). The pinprick test showed no difference in recovery depending on the number of crushes or whether or not exercised. DISCUSSION Different numbers of sciatic nerve crushes affect muscle reinnervation and motor neuron synaptic changes differently, but motor function recovery may improve with exercise regardless of the number of crushes. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Yuki Minegishi
- Graduate Course of Health and Social Services, Graduate School of Saitama Prefectural University, Saitama, Japan.,Research Fellowship for Young Scientists, Japan Society for the Promotion of Science, Tokyo, Japan
| | - Junji Nishimoto
- Department of Rehabilitation, Saitama Medical University Saitama Medical Center, Saitama, Japan
| | - Minori Uto
- Graduate Course of Health and Social Services, Graduate School of Saitama Prefectural University, Saitama, Japan
| | - Kaichi Ozone
- Graduate Course of Health and Social Services, Graduate School of Saitama Prefectural University, Saitama, Japan.,Research Fellowship for Young Scientists, Japan Society for the Promotion of Science, Tokyo, Japan
| | - Yuichiro Oka
- Graduate Course of Health and Social Services, Graduate School of Saitama Prefectural University, Saitama, Japan.,Research Fellowship for Young Scientists, Japan Society for the Promotion of Science, Tokyo, Japan
| | - Takanori Kokubun
- Department of Physical Therapy, Faculty of Health and Social Services, Saitama Prefectural University, Saitama, Japan
| | - Kenji Murata
- Department of Physical Therapy, Faculty of Health and Social Services, Saitama Prefectural University, Saitama, Japan
| | - Hidenori Takemoto
- Department of Rehabilitation, Hiroshima International Medical and Welfare College, Hiroshima, Japan
| | - Naohiko Kanemura
- Department of Physical Therapy, Faculty of Health and Social Services, Saitama Prefectural University, Saitama, Japan
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2
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Holt E, Stanton-Turcotte D, Iulianella A. Development of the Vertebrate Trunk Sensory System: Origins, Specification, Axon Guidance, and Central Connectivity. Neuroscience 2021; 458:229-243. [PMID: 33460728 DOI: 10.1016/j.neuroscience.2020.12.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 12/09/2020] [Accepted: 12/31/2020] [Indexed: 12/26/2022]
Abstract
Crucial to an animal's movement through their environment and to the maintenance of their homeostatic physiology is the integration of sensory information. This is achieved by axons communicating from organs, muscle spindles and skin that connect to the sensory ganglia composing the peripheral nervous system (PNS), enabling organisms to collect an ever-constant flow of sensations and relay it to the spinal cord. The sensory system carries a wide spectrum of sensory modalities - from sharp pain to cool refreshing touch - traveling from the periphery to the spinal cord via the dorsal root ganglia (DRG). This review covers the origins and development of the DRG and the cells that populate it, and focuses on how sensory connectivity to the spinal cord is achieved by the diverse developmental and molecular processes that control axon guidance in the trunk sensory system. We also describe convergences and differences in sensory neuron formation among different vertebrate species to gain insight into underlying developmental mechanisms.
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Affiliation(s)
- Emily Holt
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, and Brain Repair Centre, Life Science Research Institute, 1348 Summer Street, Halifax, Nova Scotia B3H-4R2, Canada
| | - Danielle Stanton-Turcotte
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, and Brain Repair Centre, Life Science Research Institute, 1348 Summer Street, Halifax, Nova Scotia B3H-4R2, Canada
| | - Angelo Iulianella
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, and Brain Repair Centre, Life Science Research Institute, 1348 Summer Street, Halifax, Nova Scotia B3H-4R2, Canada.
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3
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Lopez AJ, Xu J, Hoque MM, McMullen C, Kesar TM, Borich MR. Integration of Convergent Sensorimotor Inputs Within Spinal Reflex Circuits in Healthy Adults. Front Hum Neurosci 2020; 14:592013. [PMID: 33324184 PMCID: PMC7725688 DOI: 10.3389/fnhum.2020.592013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 11/03/2020] [Indexed: 11/25/2022] Open
Abstract
The output from motor neuron pools is influenced by the integration of synaptic inputs originating from descending corticomotor and spinal reflex pathways. In this study, using paired non-invasive brain and peripheral nerve stimulation, we investigated how descending corticomotor pathways influence the physiologic recruitment order of the soleus Hoffmann (H-) reflex. Eleven neurologically unimpaired adults (9 females; mean age 25 ± 3 years) completed an assessment of transcranial magnetic stimulation (TMS)-conditioning of the soleus H-reflex over a range of peripheral nerve stimulation (PNS) intensities. Unconditioned H-reflex recruitment curves were obtained by delivering PNS pulses to the posterior tibial nerve. Subsequently, TMS-conditioned H-reflex recruitment curves were obtained by pairing PNS with subthreshold TMS at short (−1.5 ms) and long (+10 ms) intervals. We evaluated unconditioned and TMS-conditioned H-reflex amplitudes along the ascending limb, peak, and descending limb of the H-reflex recruitment curve. Our results revealed that, for long-interval facilitation, TMS-conditioned H-reflex amplitudes were significantly larger than unconditioned H-reflex amplitudes along the ascending limb and peak of the H-reflex recruitment curve. Additionally, significantly lower PNS intensities were needed to elicit peak H-reflex amplitude (Hmax) for long-interval facilitation compared to unconditioned. These findings suggest that the influence of descending corticomotor pathways, particularly those mediating long-interval facilitation, contribute to changing the recruitment gain of the motor neuron pool, and can inform future methodological protocols for TMS-conditioning of H-reflexes. By characterizing and inducing short-term plasticity in circuitry mediating short- and long-interval TMS-conditioning of H-reflex amplitudes, future studies can investigate supraspinal and spinal circuit contributions to abnormal motor control, as well as develop novel therapeutic targets for neuromodulation.
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Affiliation(s)
- Alejandro J Lopez
- Neural Plasticity Research Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States.,Motion Analysis Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States
| | - Jiang Xu
- Neural Plasticity Research Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States.,Motion Analysis Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States.,Department of Rehabilitation Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Maruf M Hoque
- Neural Plasticity Research Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States.,Motion Analysis Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States
| | - Carly McMullen
- Neural Plasticity Research Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States.,Motion Analysis Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States
| | - Trisha M Kesar
- Motion Analysis Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States
| | - Michael R Borich
- Neural Plasticity Research Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States
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Oki K, Wei B, Feng HZ, Jin JP. The loss of slow skeletal muscle isoform of troponin T in spindle intrafusal fibres explains the pathophysiology of Amish nemaline myopathy. J Physiol 2019; 597:3999-4012. [PMID: 31148174 PMCID: PMC6675633 DOI: 10.1113/jp278119] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 05/29/2019] [Indexed: 01/17/2023] Open
Abstract
KEY POINTS The pathogenic mechanism and the neuromuscular reflex-related phenotype (e.g. tremors accompanied by clonus) of Amish nemaline myopathy, as well as of other recessively inherited TNNT1 myopathies, remain to be clarified. The truncated slow skeletal muscle isoform of troponin T (ssTnT) encoded by the mutant TNNT1 gene is unable to incorporate into myofilaments and is degraded in muscle cells. By contrast to extrafusal muscle fibres, spindle intrafusal fibres of normal mice contain a significant level of cardiac TnT and a low molecular weight splice form of ssTnT. Intrafusal fibres of ssTnT-knockout mice have significantly increased cardiac TnT. Rotarod and balance beam tests have revealed abnormal neuromuscular co-ordination in ssTnT-knockout mice and a blunted response to a spindle sensitizer, succinylcholine. The loss of ssTnT and a compensatory increase of cardiac TnT in intrafusal nuclear bag fibres may increase myofilament Ca2+ -sensitivity and tension, impairing spindle function, thus identifying a novel mechanism for the development of targeted treatment. ABSTRACT A nonsense mutation at codon Glu180 of TNNT1 gene causes Amish nemaline myopathy (ANM), a recessively inherited disease with infantile lethality. TNNT1 encodes the slow skeletal muscle isoform of troponin T (ssTnT). The truncated ssTnT is unable to incorporate into myofilament and is degraded in muscle cells. The symptoms of ANM include muscle weakness, atrophy, contracture and tremors accompanied by clonus. An ssTnT-knockout (KO) mouse model recapitulates key features of ANM such as atrophy of extrafusal slow muscle fibres and increased fatigability. However, the neuromuscular reflex-related symptoms of ANM have not been explained. By isolating muscle spindles from ssTnT-KO and control mice aiming to examine the composition of myofilament proteins, we found that, in contrast to extrafusal fibres, intrafusal fibres contain a significant level of cardiac TnT and the low molecular weight splice form of ssTnT. Intrafusal fibres from ssTnT-KO mice have significantly increased cardiac TnT. Rotarod and balance beam tests revealed impaired neuromuscular co-ordination in ssTnT-KO mice, indicating abnormality in spindle functions. Unlike the wild-type control, the beam running ability of ssTnT-KO mice had a blunted response to a spindle sensitizer, succinylcholine. Immunohistochemistry detected ssTnT and cardiac TnT in nuclear bag fibres, whereas fast skeletal muscle TnT was detected in nuclear chain fibres, and cardiac α-myosin was present in one of the two nuclear bag fibres. The loss of ssTnT and a compensatory increase of cardiac TnT in nuclear bag fibres would increase myofilament Ca2+ -sensitivity and tension, thus affecting spindle activities. This mechanism provides an explanation for the pathophysiology of ANM, as well as a novel target for treatment.
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Affiliation(s)
| | | | - Han-Zhong Feng
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - J.-P. Jin
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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5
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Asano K, Nakano T, Tokutake K, Ishii H, Nishizuka T, Iwatsuki K, Onishi T, Kurimoto S, Yamamoto M, Tatebe M, Hirata H. Muscle spindle reinnervation using transplanted embryonic dorsal root ganglion cells after peripheral nerve transection in rats. Cell Prolif 2019; 52:e12660. [PMID: 31264327 PMCID: PMC6797520 DOI: 10.1111/cpr.12660] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 05/13/2019] [Accepted: 06/06/2019] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVES Muscle spindles are proprioceptive receptors in the skeletal muscle. Peripheral nerve injury results in a decreased number of muscle spindles and their morphologic deterioration. However, the muscle spindles recover when skeletal muscles are reinnervated with surgical procedures, such as nerve suture or nerve transfer. Morphological changes in muscle spindles by cell transplantation procedure have not been reported so far. Therefore, we hypothesized that transplantation of embryonic sensory neurons may improve sensory neurons in the skeletal muscle and reinnervate the muscle spindles. MATERIALS AND METHODS We collected sensory neurons from dorsal root ganglions of 14-day-old rat embryos and prepared a rat model of peripheral nerve injury by performing sciatic nerve transection and allowing for a period of one week before which we performed the cell transplantations. Six months later, the morphological changes of muscle spindles in the cell transplantation group were compared with the naïve control and surgical control groups. RESULTS Our results demonstrated that transplantation of embryonic dorsal root ganglion cells induced regeneration of sensory nerve fibre and reinnervation of muscle spindles in the skeletal muscle. Moreover, calbindin D-28k immunoreactivity in intrafusal muscle fibres was maintained for six months after denervation in the cell transplantation group, whereas it disappeared in the surgical control group. CONCLUSIONS Cell transplantation therapies could serve as selective targets to modulate mechanosensory function in the skeletal muscle.
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Affiliation(s)
- Kenichi Asano
- Department of Hand Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tomonori Nakano
- Department of Hand Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Katsuhiro Tokutake
- Department of Hand Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hisao Ishii
- Department of Hand Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Takanobu Nishizuka
- Department of Hand Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Katsuyuki Iwatsuki
- Department of Hand Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tetsuro Onishi
- Department of Hand Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shigeru Kurimoto
- Department of Hand Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Michiro Yamamoto
- Department of Hand Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masahiro Tatebe
- Department of Hand Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hitoshi Hirata
- Department of Hand Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
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7
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Duricki DA, Hutson TH, Kathe C, Soleman S, Gonzalez-Carter D, Petruska JC, Shine HD, Chen Q, Wood TC, Bernanos M, Cash D, Williams SCR, Gage FH, Moon LDF. Delayed intramuscular human neurotrophin-3 improves recovery in adult and elderly rats after stroke. Brain 2015; 139:259-75. [PMID: 26614754 PMCID: PMC4785394 DOI: 10.1093/brain/awv341] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 09/29/2015] [Indexed: 12/11/2022] Open
Abstract
There is an urgent need for a therapy that reverses disability after stroke when initiated in a time frame suitable for the majority of new victims. We show here that intramuscular delivery of neurotrophin-3 (NT3, encoded by NTF3) can induce sensorimotor recovery when treatment is initiated 24 h after stroke. Specifically, in two randomized, blinded preclinical trials, we show improved sensory and locomotor function in adult (6 months) and elderly (18 months) rats treated 24 h following cortical ischaemic stroke with human NT3 delivered using a clinically approved serotype of adeno-associated viral vector (AAV1). Importantly, AAV1-hNT3 was given in a clinically-feasible timeframe using a straightforward, targeted route (injections into disabled forelimb muscles). Magnetic resonance imaging and histology showed that recovery was not due to neuroprotection, as expected given the delayed treatment. Rather, treatment caused corticospinal axons from the less affected hemisphere to sprout in the spinal cord. This treatment is the first gene therapy that reverses disability after stroke when administered intramuscularly in an elderly body. Importantly, phase I and II clinical trials by others show that repeated, peripherally administered high doses of recombinant NT3 are safe and well tolerated in humans with other conditions. This paves the way for NT3 as a therapy for stroke.
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Affiliation(s)
- Denise A Duricki
- 1 Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London, 16-18 Newcomen Street, London SE1 1UL, UK 2 Centre for Integrative Biology, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK
| | - Thomas H Hutson
- 1 Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London, 16-18 Newcomen Street, London SE1 1UL, UK 3 Division of Brain Sciences, Department of Medicine, Hammersmith Campus, Imperial College London, London, UK
| | - Claudia Kathe
- 1 Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London, 16-18 Newcomen Street, London SE1 1UL, UK
| | - Sara Soleman
- 1 Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London, 16-18 Newcomen Street, London SE1 1UL, UK 4 John Van Geest Centre for Brain Repair University of Cambridge, The E.D. Adrian Building, Forvie Site, Robinson Way Cambridge, CB2 0PY, UK
| | - Daniel Gonzalez-Carter
- 1 Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London, 16-18 Newcomen Street, London SE1 1UL, UK 3 Division of Brain Sciences, Department of Medicine, Hammersmith Campus, Imperial College London, London, UK
| | - Jeffrey C Petruska
- 5 Department of Anatomical Sciences and Neurobiology, University of Louisville; Kentucky Spinal Cord Injury Research Center, Department of Neurological Surgery, Louisville, Kentucky, USA
| | - H David Shine
- 6 Center for Cell and Gene Therapy, Department of Neuroscience, Alkek Bldg N1130.01, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - Qin Chen
- 6 Center for Cell and Gene Therapy, Department of Neuroscience, Alkek Bldg N1130.01, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - Tobias C Wood
- 7 Neuroimaging Research Group, King's College London, PO42 De Crespigny Park, London, SE5 8AF, UK
| | - Michel Bernanos
- 7 Neuroimaging Research Group, King's College London, PO42 De Crespigny Park, London, SE5 8AF, UK
| | - Diana Cash
- 7 Neuroimaging Research Group, King's College London, PO42 De Crespigny Park, London, SE5 8AF, UK
| | - Steven C R Williams
- 7 Neuroimaging Research Group, King's College London, PO42 De Crespigny Park, London, SE5 8AF, UK
| | - Fred H Gage
- 8 The Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - Lawrence D F Moon
- 1 Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London, 16-18 Newcomen Street, London SE1 1UL, UK 2 Centre for Integrative Biology, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK
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8
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Sierra E, Fernández A, Espinosa de los Monteros A, Díaz-Delgado J, Bernaldo de Quirós Y, García-Álvarez N, Arbelo M, Herráez P. Comparative histology of muscle in free ranging cetaceans: shallow versus deep diving species. Sci Rep 2015; 5:15909. [PMID: 26514564 PMCID: PMC4626863 DOI: 10.1038/srep15909] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 10/05/2015] [Indexed: 12/19/2022] Open
Abstract
Different marine mammal species exhibit a wide range of diving behaviour based on their breath-hold diving capabilities. They are classically categorized as long duration, deep-diving and short duration, shallow-diving species. These abilities are likely to be related to the muscle characteristics of each species. Despite the increasing number of publications on muscle profile in different cetacean species, very little information is currently available concerning the characteristics of other muscle components in these species. In this study, we examined skeletal muscle fiber type, fiber size (cross sectional area and lesser diameter), intramuscular substrates, and perimysium-related structures, by retrospective study in 146 stranded cetaceans involving 15 different species. Additionally, we investigated diving profile-specific histological features. Our results suggest that deep diving species have higher amount of intramyocyte lipid droplets, and evidence higher percentage of intramuscular adipose tissue, and larger fibre sizes in this group of animals.
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Affiliation(s)
- E Sierra
- Department of Veterinary Pathology, Institute for Animal Health, Veterinary School, University of Las Palmas de Gran Canaria, Spain
| | - A Fernández
- Department of Veterinary Pathology, Institute for Animal Health, Veterinary School, University of Las Palmas de Gran Canaria, Spain
| | - A Espinosa de los Monteros
- Department of Veterinary Pathology, Institute for Animal Health, Veterinary School, University of Las Palmas de Gran Canaria, Spain
| | - J Díaz-Delgado
- Department of Veterinary Pathology, Institute for Animal Health, Veterinary School, University of Las Palmas de Gran Canaria, Spain
| | - Y Bernaldo de Quirós
- Department of Veterinary Pathology, Institute for Animal Health, Veterinary School, University of Las Palmas de Gran Canaria, Spain
| | - N García-Álvarez
- Department of Veterinary Pathology, Institute for Animal Health, Veterinary School, University of Las Palmas de Gran Canaria, Spain
| | - M Arbelo
- Department of Veterinary Pathology, Institute for Animal Health, Veterinary School, University of Las Palmas de Gran Canaria, Spain
| | - P Herráez
- Department of Veterinary Pathology, Institute for Animal Health, Veterinary School, University of Las Palmas de Gran Canaria, Spain
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Mendelsohn AI, Simon CM, Abbott LF, Mentis GZ, Jessell TM. Activity Regulates the Incidence of Heteronymous Sensory-Motor Connections. Neuron 2015; 87:111-23. [PMID: 26094608 DOI: 10.1016/j.neuron.2015.05.045] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 04/23/2015] [Accepted: 05/26/2015] [Indexed: 12/19/2022]
Abstract
The construction of spinal sensory-motor circuits involves the selection of appropriate synaptic partners and the allocation of precise synaptic input densities. Many aspects of spinal sensory-motor selectivity appear to be preserved when peripheral sensory activation is blocked, which has led to a view that sensory-motor circuits are assembled in an activity-independent manner. Yet it remains unclear whether activity-dependent refinement has a role in the establishment of connections between sensory afferents and those motor pools that have synergistic biomechanical functions. We show here that genetically abolishing central sensory-motor neurotransmission leads to a selective enhancement in the number and density of such "heteronymous" connections, whereas other aspects of sensory-motor connectivity are preserved. Spike-timing-dependent synaptic refinement represents one possible mechanism for the changes in connectivity observed after activity blockade. Our findings therefore reveal that sensory activity does have a limited and selective role in the establishment of patterned monosynaptic sensory-motor connections.
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Affiliation(s)
- Alana I Mendelsohn
- Howard Hughes Medical Institute, Kavli Institute for Brain Science, Zuckerman Mind Brain Behavior Institute, Departments of Neuroscience and Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Christian M Simon
- Center for Motor Neuron Biology and Disease, Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - L F Abbott
- Center for Theoretical Neuroscience, Departments of Physiology and Neuroscience, Columbia University, New York, NY 10032, USA
| | - George Z Mentis
- Center for Motor Neuron Biology and Disease, Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Thomas M Jessell
- Howard Hughes Medical Institute, Kavli Institute for Brain Science, Zuckerman Mind Brain Behavior Institute, Departments of Neuroscience and Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
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10
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Neuronal BDNF signaling is necessary for the effects of treadmill exercise on synaptic stripping of axotomized motoneurons. Neural Plast 2015; 2015:392591. [PMID: 25918648 PMCID: PMC4397030 DOI: 10.1155/2015/392591] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 03/09/2015] [Accepted: 03/16/2015] [Indexed: 11/18/2022] Open
Abstract
The withdrawal of synaptic inputs from the somata and proximal dendrites of spinal motoneurons following peripheral nerve injury could contribute to poor functional recovery. Decreased availability of neurotrophins to afferent terminals on axotomized motoneurons has been implicated as one cause of the withdrawal. No reduction in contacts made by synaptic inputs immunoreactive to the vesicular glutamate transporter 1 and glutamic acid decarboxylase 67 is noted on axotomized motoneurons if modest treadmill exercise, which stimulates the production of neurotrophins by spinal motoneurons, is applied after nerve injury. In conditional, neuron-specific brain-derived neurotrophic factor (BDNF) knockout mice, a reduction in synaptic contacts onto motoneurons was noted in intact animals which was similar in magnitude to that observed after nerve transection in wild-type controls. No further reduction in coverage was found if nerves were cut in knockout mice. Two weeks of moderate daily treadmill exercise following nerve injury in these BDNF knockout mice did not affect synaptic inputs onto motoneurons. Treadmill exercise has a profound effect on synaptic inputs to motoneurons after peripheral nerve injury which requires BDNF production by those postsynaptic cells.
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11
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Development of twitching in sleeping infant mice depends on sensory experience. Curr Biol 2015; 25:656-62. [PMID: 25702578 DOI: 10.1016/j.cub.2015.01.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 12/23/2014] [Accepted: 01/07/2015] [Indexed: 01/15/2023]
Abstract
Myoclonic twitches are jerky movements that occur exclusively and abundantly during active (or REM) sleep in mammals, especially in early development [1-4]. In rat pups, limb twitches exhibit a complex spatiotemporal structure that changes across early development [5]. However, it is not known whether this developmental change is influenced by sensory experience, which is a prerequisite to the notion that sensory feedback from twitches not only activates sensorimotor circuits but modifies them [4]. Here, we investigated the contributions of proprioception to twitching in newborn ErbB2 conditional knockout mice that lack muscle spindles and grow up to exhibit dysfunctional proprioception [6-8]. High-speed videography of forelimb twitches unexpectedly revealed a category of reflex-like twitching-comprising an agonist twitch followed immediately by an antagonist twitch-that developed postnatally in wild-types/heterozygotes, but not in knockouts. Contrary to evidence from adults that spinal reflexes are inhibited during twitching [9-11], this finding suggests that twitches trigger the monosynaptic stretch reflex and, by doing so, contribute to its activity-dependent development [12-14]. Next, we assessed developmental changes in the frequency and organization (i.e., entropy) of more-complex, multi-joint patterns of twitching; again, wild-types/heterozygotes exhibited developmental changes in twitch patterning that were not seen in knockouts. Thus, targeted deletion of a peripheral sensor alters the normal development of local and global features of twitching, demonstrating that twitching is shaped by sensory experience. These results also highlight the potential use of twitching as a uniquely informative diagnostic tool for assessing the functional status of spinal and supraspinal circuits.
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12
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Formation of cholinergic synapse-like specializations at developing murine muscle spindles. Dev Biol 2014; 393:227-235. [DOI: 10.1016/j.ydbio.2014.07.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 07/14/2014] [Accepted: 07/15/2014] [Indexed: 12/30/2022]
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Xie P, Jiang Y, Zhang X, Yang S. The study of intramuscular nerve distribution patterns and relative spindle abundance of the thenar and hypothenar muscles in human hand. PLoS One 2012; 7:e51538. [PMID: 23251569 PMCID: PMC3519735 DOI: 10.1371/journal.pone.0051538] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 11/08/2012] [Indexed: 01/11/2023] Open
Abstract
Background The intramuscular nerve distribution and relative spindle abundance of the human hand have not been well defined, although this is important in guiding hand surgery. Methods Forty human hands were dissected and subjected to modified Sihler’s stain and haematoxylin and eosin stain to investigate intramuscular nerve distribution and relative spindle abundance, respectively. Results The flexor pollicis brevis (FPB), adductor pollicis (AP), and abductor digiti minimi (ADM) contain separate nerve compartments. Neural anastomoses were observed in the thenar and hypothenar muscles, including the Y-like, O-like, H-like, and U-like appearance. We found that U-like neural anastomoses may be the characteristic of the opponens muscles. The relative spindle abundance was the greatest in the opponens muscles which may coordinate fine movements. Conclusion Except for the two opponens muscles, the rest of the thenar and hypothenar muscles could be used as whole muscle or half-muscle donors for muscle transplant. Our nerve map of the hand offers valuable guidance for hand reconstruction.
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Affiliation(s)
- Peng Xie
- Department of Anatomy, Zunyi Medical College, Zunyi, Guizhou, People's Republic of China
| | - Yanjun Jiang
- Department of Anatomy, Zunyi Medical College, Zunyi, Guizhou, People's Republic of China
| | - Xiaoming Zhang
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Shengbo Yang
- Department of Anatomy, Zunyi Medical College, Zunyi, Guizhou, People's Republic of China
- * E-mail:
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